Two-cycle internal-combustion engine.



O. R. P. BERGLUND. TWO CYCLE INTERNAL COMBUSTION ENGINE.

APPLICATION FILED AUG.21.1912.

Patented Dec. 7, 1915.

L Inventor witnesses OTTO ROBERT PERCIVAL BERGLUND, 0F STOGKHOLM, SWEDEN.

TWO-CYCLE INTERNAL-COMBUSTION ENGINE.

Application filed August 21, 1912.

f0 all whom it may concern:

Be it known that T, ()T'ro ROBERT PERCI- VAL BERG-LUND, a subject of the King of Sweden, residing at Stockholm, in the Kingdom of Sweden, have invented new and useful improvements in Two-Cycle Internal- Combustion Engines, of which the following is a specification, reference being had to the drawing accompanying and forming part thereof.

My invention relates to improvements in two-cycle internal combustion engines, especially such as are required to run at high speed.

The object of my invention is to provide a motor in which the air, necessary for the cleaning of the cylinder and for mixing in the right proportion with the gas to be ignited, may be delivered to the cylinder in suiiicient quantity and entirely free from impurities.

Other objects are to simplify the construction of such a motor, to make its essential parts, such as the piston and the interior of the cylinder, easily accessible, and to effect an eflicient cooling of the cylinder, the piston and the piston-rod.

To gain these objects my invention consists mainly in. a, two-cycle internal combustion engine comprising the combination of a cylinder, a tube open at both ends fastened to one end of the cylinder and extending through its explosion chamber, a hollow piston within the cylinder arranged to slide on the tube, and a rod extending through the tube and fastened to the piston. At the other end of the cylinder is arranged a compression chamber between the piston and an elongation of the cylinder, or--m0re suitably-between the piston and a separate cap securely fastened to the end of the cylinder. The piston-rod is arranged to reciprocate within the tube without touching it, appreciable clearance being provided between the rod and the interior surface of the tube. The piston rod, however, may extend toward the opposite end, that is through the compression chamber, if it be provided with. a necessary and suitable packing box. In either case the arrangement is such that the outside air has access through the tube to the hollow interior of the piston so that air sucked into the piston will cool the piston and its rod and may even through special arrangements be used for cooling also other parts of the motor.

Specification of Letters Patent.

Patented Dec. 7, 1915.

Serial No. 716,117.

My invention is illustrated in the accompanying drawing in which Figure l is a vertical sectional view of the cylinder of the motor, and Fig. 2 shows a modification of the construction illustrated in Fig. 1. Fig. 3 is a cross sectional view, the section being taken on the line AB of Fig. 1 and Figs. 4 and 5 illustrate details.

Referring to the drawings in detail, a; represents the cylinder, the bottom formed in tegrally with the cylinder, and c the tube open at both ends fastened to the bottom and extending into the cylinder.

(Z represents the piston, formed with a hollow interior 6 which has a sliding fit on the tube. A packing f is provided between the tube and the inside of the piston, and a packing 9 between the piston and the inside of the cylinder. The piston rod h is fastened 'to the piston, and extends with appreciable clearance through the tube. The

- open end of the cylinder is closed by a cap a, securely fastened to the cylinder and forming together with the piston the coInpression chamber of the cylinder. When the piston (Z has completed a working stroke it occupies such a position as shown in Fig. 1 that the compression chamber communicates with the explosion chamber through the openings 2' in the cylinder, the canals in in the piston, and the channels Zin the tube, and consequently the air compressed within the formerwill expel the burnt gases from the explosion chamber through the exhaust openings on. The igniting devices, not shown on the'drawing are located in the openings n/ The outside air will enter the cap a when during the compression stroke the edge of the piston [Z comes inside of an opening 0 in the wall of the cylinder (see Fig. 4).

The locating of the compression chamber within the cap affords the advantage that the air cannot possibly be fouled since the said compression chamber and the passages connected thereto do not contain substances effecting such fouling, which, on the contrary, is the case when, as usual, the crank casing containing lubricating substances fouled by the wear and tear of the engine parts, dust, etc., forms the compression chamber. The volume within the capand thus the quantity of the air-can easily be given its correct proportion because the dimensions and the form of the cap can be chosen so as to correspond exactly to the required quantity of air. In addition'especially whenthe piston rod is arranged as shown on the drawing .the air compressing area of the piston Will'qbe appreciably greater than the piston area exposed to the workingpressure, whereby the pressure and the quantity of the compressed air will be greater than in common two cycle engines in which the compression of air is effected by the same piston area as is exposed to the working pressure. The relatively large quantity of air, which is necessary for blowing the cylinder perfectly clean when ordinary kerosene is used for operating the motor, can thus be obtained without difficulty.

I11 order to prevent any possibility of igniting a mixture of gases compressed within the channels Z, I prefer to separate said channels completely from the explosion chamber when the piston occupies its lowest position by means of the collar p formed with the piston and inclosing the tube, and arranged to cover the mouth Q of the channel Z. The tube 0 isprovided not only with the above described airchannels Z but also with the air channels 1' (Fig. which extend through the whole length of the tube and thus give free access for the outside air to be sucked through the tube into the hol- 10w interior 6 of the piston, and also to be expelled therefrom, thus carrying away a considerable amount of heat and efficiently cooling the piston and its rod.

Fig. 2 shows a modification in which the air from the compression chamber for blowing the cylinder clean is not conveyed through channels in the tube but through a canal s from which the air enters direct into the working room and from there passes to the exhaust t. The tube 0 in Fig. 2 is also so arranged in relation to the piston rod that air is alternately sucked into and expelled from the hollow interior 6 of the piston. By detaching the cap u from the cylinder, free access is provided to the piston,.the piston rod and the interior-of the cylinder. The other parts of the motor mechanism such as the connecting rod and the crankshaft and allied parts are all the time accessible, since they are not covered by any closed casing.

Fig. 5 shows a modified form of the invention in which the piston rod h extends through the cap a by means of a packing box 1).

Having thus I claim is:

1. In a two-cycle internal combustion engine, the combination of a cylinder forming anexplosion chamber, a tube secured in the described my invention, what end of the cylinder adjacent to the shaft of the engine and extending through the cylinder, a piston within the cylinder adapted to slide on the tube, and an air compression chamber communicating with the cylinder at the opposite side of the piston from the shaft of the engine, substantially as and for the purpose set forth.

2. In a' two-cycle internal combustion engine, the combination of a cylinder forming an explosion chamber, a tube secured in the end of the cylinder adjacent to the shaft of the engine and extending through the cylinder, a hollow piston within the cylinder adapted to slide on the tube, a rod secured to the piston and extending through the tube, passages in said tube communicating with the hollow of the piston and with the outside of the engine, and an air compression chamber communicating with the cylinder at the opposite side of the piston from the shaft of the engine, substantially as and for the purpose set forth.

3. In a two-cycle internal combustion engine, the combination of a cylinder forming an explosion chamber, a tube secured in the end of the cylinder adjacent to the shaft of the engine and extending through the cylinder, a hollow piston within the cylinder adapted to slide on the tube, a rod secured to the piston and extending through the tube, a space in the tube between its inside walls and the rod, and an air compression chamber communicating with the cylinder at the opposite side of the piston from the shaft of the engine, substantially as and for the purpose set forth.

4. In a two-cycle internal combustion engine, the combination of a cylinder forming an explosion chamber, a tube secured in the end of the cylinder adjacent to the shaft of the engine and extending through the cylinder, a hollow piston within the cylinder and adapted to slide on the tube, a rod secured to the piston and extending through the tube, passages in said tube communicating with the hollow of the piston and with the outside of the engine, an air compression chamber communicating with the cylinder at the opposite side of the piston from the shaft of the engine, and a channel in said tube arranged to establish a connection between the explosion chamber and the air compression chamber at the end of a stroke of the piston, substantially as and for the purpose set forth.

OTTO ROBERT PERCIVAL BERGLUND.

Witnesses:

K. E. NEIBERG, KoUR. DAHLQUIS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. C. 

